I kept getting calls and texts for Stephen for a while. All I found out about him was that he lived in the North of England. I assumed that he had given out his number with a digit wrong so that it was actually mine, and there was no way that I could think of to get in touch with him to stop it. In the end, it just stopped, and I hope the same happens for you, pat834. Like you, I've had my phone for over 10 years.
For a while I was getting drunken calls, usually in the middle of the night, from some woman who accused be of treating her badly. Fortunately I turn my phone off at night! In the end I phoned her back and told her she had the wrong number, and she stopped, thank goodness.